Hysteresis elastomeric compositions comprising sequentially terminated polymers

ABSTRACT

Anionically-polymerized living polymers are sequentially functionalized with certain agents X′ and Y′. A method of preparing a functionalized polymer comprising the steps of reacting the polymer with a functionalizing agent X′, and then further reacting the polymer with a functionalizing agent Y′.

This application gains benefit from U.S. Patent Provisional ApplicationNo. 60/477,013, filed Jun. 9, 2003, and PCT/US0₄/18286, filed Jun. 9,2004.

FIELD OF THE INVENTION

This invention relates to functionalized polymers containing carbonblack-reactive and silica-reactive functionalities and methods formaking the same. The functionalized polymers are useful in fabricatingtires.

BACKGROUND OF THE INVENTION

In the art of making tires, it is desirable to employ rubbervulcanizates that demonstrate reduced hysteresis loss, i.e., less lossof mechanical energy to heat. Hysteresis loss is often attributed topolymer free ends within the cross-linked rubber network, as well as thedisassociation of filler agglomerates. The proportion of bound rubberwithin the vulcanizate is also important, as increased bound rubberprovides better wear resistance.

Functionalized polymers have been employed to reduce hysteresis loss andincrease bound rubber. The functional group of the functionalizedpolymer is believed to interact with a filler particle and therebyreduce the number of polymer free ends. Also, the interaction betweenthe functional group and the filler particles reduces filleragglomeration, which thereby reduces hysteretic losses attributable tothe disassociation of filler agglomerates (i.e., Payne effect).

Conjugated diene monomers are often anionically polymerized by usingalkyllithium compounds as initiators. Selection of certain alkyllithiumcompounds can provide a polymer product having functionality at the headof the polymer chain. A functional group can also be attached to thetail end of an anionically-polymerized polymer by terminating a livingpolymer with a functionalized compound.

For example, trialkyltin chlorides, such as tributyl tin chloride, havebeen employed to terminate the polym erization of conjugted dienes, aswell as the copolymerization of conjugated dienes and vinyl aromaticmonomers, to produce polymers having a trialkyltin functionality at thetail end of the polymer. These polymers have proven to betechnologically useful in the manufacture of tire treads that arecharacterized by improved traction, low rolling resistance, and improvedwear.

Because functionalized polymers are advantageous, especially in thepreparation of tire compositions, there exists a need for additionalfunctionalized polymers. Moreover, because precipitated silica has beenincreasingly used as reinforcing particulate filler in tires,functionalized elastomers having affinity to silica filler are needed.

SUMMARY OF THE INVENTION

In general the present invention provides a method for preparing asequentially functionalized polymer, the method comprising reacting ananionically polymerized living polymer with a functionalizing agent X′to produce an end-functionalized polymer that will react or interactwith carbon black, silica, or both and that comprises a reactiveelectrophilic or nucleophilic site, and reacting the reactive site witha functionalizing agent Y′ to produce a sequentially functionalizedpolymer that will react or interact with carbon black and silica.

The present invention also includes a vulcanizate prepared byvulcanizing a rubber formulation comprising at least one vulcanizablerubber and a filler, where the at least one vulcanizable rubber is asequentially functionalized polymer that is prepared by reacting ananionically polymerized living polymer with a functionalizing agent X′to produce an end-functionalized polymer that will react or interactwith carbon black, silica, or both and that comprises a reactiveelectrophilic or nucleophilic site, and reacting the reactive site witha functionalizing agent Y′ to produce a sequentially functionalizedpolymer that will react or interact with carbon black and silica.

The present invention further includes a functionalized polymer definedby the formula

X_(m)ZY_(n)where

is an anionically polymerized polymer segment, X comprises a firstfunctional group that will react or interact with carbon black, silica,or both, Y comprises a second functional group that will react orinteract with carbon black, silica, or both, Z is a bond or achain-extending group, and m and n are each integers from 1 to about 50,with the proviso that when X will react or interact with carbon blackbut not with silica, Y will react or interact with silica, and when Xwill react or interact with silica but not with carbon black, Y willreact or interact with carbon black.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

This invention includes functionalized polymers defined by the formula

X_(m)ZY_(n)where

is an anionically polymerized polymer, X comprises a functional groupthat will react or interact with carbon black, silica, or both, Ycomprises a functional group that will react or interact with carbonblack, silica, or both, Z is a bond or a chain extending group, and mand n are each integers from 1 to about 50. The chain extending group ispreferably a hydrocarbylene group. Suitable hydrocarbylene groupsinclude alkylene, cycloalkylene, substituted alkylene, substitutedcycloalkylene, alkenylene, cycloalkenylene, substituted alkenylene,substituted cycloalkenylene, arylene, and substituted arylene groups.The chain-extending group preferably contains from 1 carbon atom, or theappropriate minimum number of carbon atoms to form the group, up toabout 100 carbon atoms, more preferably up to about 75 carbon atoms,even more preferably up to about 50 carbon atoms, still more preferablyup to about 25 carbon atoms. The hydrocarbylene groups may containheteroatoms such as, but not limited to, nitrogen, oxygen, silicon,sulfur, and phosphorus atoms.

The interaction of X or Y with the filler may occur via chemicalreaction, resulting in an ionic or covalent bond between the functionalgroup and the filler particle. Alternately, the interaction of X or Ywith the filler may occur via through-space interaction (e.g., hydrogenbonding, van der Waals interaction, etc.). The interaction may be anattraction that creates a domain within the rubber matrix of thepolymer. The interaction may be an affinity toward filler particles thatis activated after processing of a vulcanized rubber formulation, e.g.during cure.

Functional groups that will react or interact with carbon black includepolar groups, basic groups, and highly aromatic groups.

Functional groups that will react or interact with silica include basicgroups and groups capable of forming hydrogen bonds, such as hydroxyl,polyalkylene glycol, epoxy, alkoxy silane, and carboxylic acid groups.Some functional groups will react or interact with both carbon black andsilica.

Preferably, due to the combined presence of X and Y, the functionalizedpolymer will react or interact with both carbon black and silica. In oneembodiment, when X comprises a functional group that will react orinteract with carbon black but not as advantageously with silica and Ycomprises a functional group that will react or interact with silica. Inanother embodiment, X comprises a functional group that will react orinteract with silica but not as advantageously with carbon black and Ycomprises a functional group that will react or interact with carbonblack.

In one embodiment, the functionalized polymers of this invention areprepared by using a sequential process. An anionically polymerizedliving polymer may be reacted with a functionalizing agent X′ to producean end-functionalized polymer that can be represented by the formula

X_(m)*where

is an anionically polymerized polymer, X and * are the residue of thereaction between the polymer and X′, * is a reactive electrophilic ornucleophilic site, and m is an integer from 1 to about 50. The reactivesite * may be reacted with a functionalizing agent Y′ to produce asequentially functionalized polymer that can be represented by theformula

X_(m)ZY_(n)where

X and m are as described above, Z is a bond, Y is the residue of thereaction between * and Y′, and n is an integer from 1 to about 50.

Compounds useful as the functionalizing agent X′ include electrophiliccompounds that will undergo an addition reaction with a living polymerto form an end-functionalized polymer that comprises a first site thatwill react or interact with carbon black and/or silica filler, and asecond reactive site * that is electrophilic or nucleophilic.

Examples of suitable X′ functionalizing agent include1,3-dimethylimidazolidinone (DMI), N-methylpyrrolidinone (NMP),carbodiimides such as dicyclohexylcarbodiimide (DCC), benzonitrile orother substituted nitrites, substituted aziridines, thiazolines,dialkylaminobenzaldehydes, bis(dialkylamino)benzophenones, substitutedepoxy compounds, N-methylcaprolactam, substituted Schiff bases,substituted styrylmethyl derivatives, vinyl pyridine, short blocks ofpolyvinylpyridine, polysulfoxides, poly(carbodiimides),poly(meth)acrylamides, poly(aminoalkyl(meth)acrylates),polyacrylonitrile, polyethylene oxide (PEO), butyl glycidyl ether,diphenyl ethylene, functionalized styrene, monoglycidyl siloxanes, andpolysiloxanes having epoxide endgroups. Examples of monoglycidylsiloxanes include 3-glycidoxypropyltrimethoxysilane (GPMOS). Examples ofpolysiloxanes having epoxide endgroups include monoglycidylether-terminated polysiloxanes such as monoglycidyl ether terminatedpoly(dimethylsiloxane). Many of these compounds are available fromAldrich Chemical Company.

In one embodiment, reactive site * may react with one or more additionalX′ functionalizing agents. In this embodiment, at least the terminal Xresidue comprises a reactive site *. This polymer terminus can beexemplified by the formula

X_(p)—X*where

, X, and * are as described above, and p is an integer from 1 to about49.

In one embodiment, where X′ is diphenyl ethylene or a functionalizedstyrene, the functionalized polymer can further polymerize conjugateddiene or vinyl aromatic monomer at reactive site * to thereby extend thepolymer chain and provide a polymer spacer between the X and Yfunctional groups.

In an alternate embodiment, the electrophilic or nucleophilic site * ofthe X portion of the polymer is selectively reactive, i.e. will reactwith certain reagents, including additional X′ functionalizing agent orY′ functionalizing agent, but will preferably not react to a substantialextent with conjugated diene or vinyl aromatic monomer to continuepropagation of the polymer.

Preferably, the end-functionalized polymer is formed by reacting an X′functionalizing agent with an anionically polymerized living polymer.Suitable anionically-polymerized living polymers can be formed byreacting anionic initiators with certain unsaturated monomers topropagate a polymeric segment having a living or reactive end. Anionicpolymerization is further described in George Odian, Principles ofPolymerization, ch. 5 (3^(rd) Ed. 1991), or Panek, 94 J. Am. Chem. Soc.,8768 (1972), which are incorporated herein by reference.

Monomers that can be employed in preparing an anionically polymerizedliving polymer include any monomer capable of being polymerizedaccording to anionic polymerization techniques. These monomers includethose that lead to the formation of elastomeric homopolymers orcopolymers. Suitable monomers include, without limitation, conjugatedC₄-C₁₂ dienes, C₈-C₈ monovinyl aromatic monomers, and C₆-C₂₀ trienes.Examples of conjugated diene monomers include, without limitation,1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and1,3-hexadiene. A non-limiting example of trienes includes myrcene.Aromatic vinyl monomers include, without limitation, styrene, ∀-methylstyrene, p-methylstyrene, and vinylnaphthalene. When preparingelastomeric copolymers, such as those containing conjugated dienemonomers and aromatic vinyl monomers, the conjugated diene monomers andaromatic vinyl monomers are normally used at a ratio of 95:5 to 50:50,and preferably 95:5 to 65:35.

One preferred type of living polymer is a copolymer of styrene and1,3-butadiene (SBR). Preferably, the styrene content of the SBRcopolymer is from about 10 to about 50 percent by weight of the totalpolymer, and more preferably from about 18 to about 40 percent by weightof the total polymer. From about 8 to about 99 percent of the unitsderived from the 1,3-butadiene are preferably of the 1,2-vinylmicrostructure, more preferably from about 10 to about 60 percent of theunits derived from the 1,3-butadiene are of the 1,2-vinylmicrostructure. Preferably, the remaining units derived from the1,3-butadiene are in the 1,4-cis- or 1,4-trans-microstructure at arelative ratio of about 3 cis-units to 5 trans-units.

Any anionic initiator can be employed to initiate the formation andpropagation of the living polymers. Preferably, the anionic initiatorcomprises at least one element from Group 1 or Group 2 of the PeriodicTable, according to the new notation of the IUPAC, as reported inHawley's Condensed Chemical Dictionary, (13^(th) Ed. 1997). The elementsin Groups 1 and 2 are commonly referred to as alkali metals and alkalineearth metals, respectively. More preferably, the anionic initiatorcomprises lithium.

Exemplary anionic initiators include, but are not limited to, alkyllithium initiators such as n-butyl lithium, arenyllithium initiators,arenylsodium initiators, N-lithium dihydro carbon amides,aminoalkyllithiums, and alkyl tin lithiums. Other useful initiatorsinclude N-lithiohexamethyleneimide, N-lithiopyrrolidinide, andN-lithiododecamethyleneimide as well as organolithium compounds such asthe alkyl lithium adducts of substituted aldimines and substitutedketimines, N-lithio salts of substituted secondary amines, andorganosulfur compounds, such as sulfur-containing heterocycles.Exemplary initiators are also described in the following U.S. Pat. Nos.:5,332,810, 5,329,005, 5,578,542, 5,393,721, 5,698,646, 5,491,230,5,521,309, 5,496,940, 5,574,109, and 5,786,441, which are incorporatedherein by reference. Preferably, the anionic polymerization is conductedin the absence of lanthanide compounds such as those used incoordination catalysis.

The amount of initiator employed in conducting anionic polymerizationscan vary widely based upon the desired polymer characteristics. In oneembodiment, it is preferred to employ from about 0.1 to about 100, andmore preferably from about 0.33 to about 10 mmol of initiator per 100 gof monomer.

Anionic polymerizations are typically conducted in a polar solvent suchas tetrahydrofuran (THF) or a nonpolar hydrocarbon such as the variouscyclic and acyclic hexanes, heptanes, octanes, pentanes, their alkylatedderivatives, and mixtures thereof, as well as benzene.

In order to promote randomization in copolymerization and to controlvinyl content, a polar coordinator may be added to the polymerizationingredients. Amounts range between 0 and 90 or more equivalents perequivalent of lithium. The amount depends on the amount of vinyldesired, the level of styrene employed and the temperature of thepolymerization, as well as the nature of the specific polar coordinator(modifier) employed. Suitable polymerization modifiers include, forexample, ethers or amines to provide the desired microstructure andrandomization of the comonomer units.

Compounds useful as polar coordinators include those having an oxygen ornitrogen heteroatom and a non-bonded pair of electrons. Examples includedialkyl ethers of mono and oligo alkylene glycols; “crown” ethers;tertiary amines such as tetramethylethylene diamine (TMEDA); linear THFoligomers; and the like. Specific examples of compounds useful as polarcoordinators include tetrahydrofuran (THF), linear and cyclic oligomericoxolanyl alkanes such as 2,2-bis(2′-tetrahydrofuryl) propane,di-piperidyl ethane, dipiperidyl methane, hexamethylphosphoramide,N-N′-dimethylpiperazine, diazabicyclooctane, dimethyl ether, diethylether, tributylamine and the like. The linear and cyclic oligomericoxolanyl alkane modifiers are described in U.S. Pat. No. 4,429,091,incorporated herein by reference.

Anionically polymerized living polymers can be prepared by either batchor continuous methods. A batch polymerization is begun by charging ablend of monomer(s) and normal alkane solvent to a suitable reactionvessel, followed by the addition of the polar coordinator (if employed)and an initiator compound. The reactants are heated to a temperature offrom about 20 to about 200° C. and the polymerization is allowed toproceed for from about 0.1 to about 24 hours. This reaction produces areactive polymer having a reactive or living end. Preferably, at leastabout 30 percent of the polymer molecules contain a living end. Morepreferably, at least about 50 percent of the polymer molecules contain aliving end.

A continuous polymerization is begun by charging monomer(s), initiatorand solvent at the same time to a suitable reaction vessel. Thereafter,a continuous procedure is followed that removes product after a suitableresidence time and replenishes the reactants.

In one embodiment, the reaction to produce end-functionalized polymercan be achieved by simply mixing the X′ functionalizing agent with theliving polymer. In a preferred embodiment, the functionalizing agent isadded once a peak polymerization temperature, which is indicative ofnearly complete monomer conversion, is observed. Because live ends mayself-terminate, it is especially preferred to add the functionalizingagent within about 25 to 35 minutes of the peak polymerizationtemperature.

The living polymer is typically contacted with X′ in a solvent ordiluent. The solvent is preferably one in which both the polymer and X′are soluble. In one embodiment, the reaction can occur in the samemedium in which the polymerization occurred.

The amount of X′ functionalizing agent is not limited, and can varywidely depending upon the functionalizing agent and the amount offunctionalization desired. In one embodiment, it is preferred to employfrom about 0.3 to about 1.1 equivalent of functionalizing agent perequivalent of initiator, more preferably, from about 0.4 to about 1.0equivalents of functionalizing agent, and even more preferably fromabout 0.5 to about 0.9 equivalents of functionalizing agent perequivalent of initiator. It will be appreciated that these numbers arebased upon the amount of initiator added to the system and may or maynot reflect the amount of initiator that is associated with the polymer.

Preferably, at least about 40 percent of the polymer molecules arefunctionalized with the X′ functionalizing agent. Even more preferably,at least about 50 percent of the polymer molecules are functionalizedwith the X′ functionalizing agent.

Optionally, the sequentially functionalized polymer may comprise a chainextending group. In one embodiment, the chain-extended X-functionalizedpolymer is prepared by reacting the reactive site * of theX-functionalized polymer with a chain-extending agent to form achain-extended polymer terminus that can be exemplified by the formula

X_(m)-Z*where

X, m and * are as described above, and Z is a hydrocarbylene group.

In one embodiment, the chain-extended functionalized polymer is preparedby reacting the reactive site * of the X-functionalized polymer with anacrylate , acrylonitrile, or acrylamide monomer, or other monomer thatwill polymerize upon reaction with the reactive site *, to form achain-extended polymer terminus.

The reactive site * is preferably reacted with a functionalizing agentY′ to produce a sequentially functionalized polymer. Compounds useful asthe Y′ functionalizing agent include electrophilic compounds that willundergo nucleophilic addition or substitution with the reactive site *to form a sequentially terminated polymer that can be represented by theformula

X_(m)ZY_(n)

where

X, and m are as described above, Z is a bond or a chain-extending group,Y is the residue of the reaction between * and Y′, and n is an integerfrom 1 to about 50. Y preferably includes at least one site that willreact or interact with carbon black and/or silica filler in a vulcanizedrubber formulation. In one embodiment, Y further comprises at least oneelectrophilic or nucleophilic site that is selectively reactive, i.e.will react with additional Y′ functionalizing agent or a monomer, butpreferably will not react with conjugated diene or vinyl aromaticmonomer, or at least will not react to a substantial extent. Usefulmonomer that will preferably react with the site include acrylates,methacrylates, acrylamides, and styrenes.

Examples of suitable Y′ functionalizing compounds include silanes,alkoxy silanes, alkoxy alkyl silanes, alkoxy halo alkyl silanes,isocyanato alkoxysilanes, epoxy-generating reagents, substituted acidchlorides, substituted isocyanates, substituted benzylic and allylichalides, substituted α,β-unsaturated ketones, α,β-unsaturated esters,α,β-unsaturated amides, and bis(dialkylamino)phosphoryl chlorides. Otheruseful Y′ compounds include functionalized acrylates, methacrylates, andstyrenes as well as acrylamides.

Isocyanato alkoxysilane compounds useful as the terminators of thepresent invention include compounds represented by the general formula:A=C═N—R¹—Si(R²)_(y)(OR³)_(3-y)where A is oxygen or sulfur, R¹ is a divalent organic group, each R² andR³ is a monovalent organic group, and y is an integer from 0 to 2. WhereA is sulfur, the above formula represents an isothiocyanato alkoxysilanecompound. Therefore, the designation “isocyanato alkoxysilane” alsorefers to isothiocyanato alkoxysilane compounds. Isocyanato alkoxysilanecompounds are described, for example, in U.S. Pat. No. 4,146,585, whichis incorporated herein by reference.

The divalent organic group is preferably a hydrocarbylene group such as,but not limited to, alkylene, cycloalkylene, substituted alkylene,substituted cycloalkylene, alkenylene, cycloalkenylene, substitutedalkenylene, substituted cycloalkenylene, arylene, and substitutedarylene groups, with each group preferably containing from 1 carbonatom, or the appropriate minimum number of carbon atoms to form thegroup, up to about 20 carbon atoms. These hydrocarbylene groups maycontain heteroatoms such as, but not limited to, nitrogen, oxygen,silicon, sulfur, and phosphorus atoms.

The monovalent organic groups are preferably hydrocarbyl groups such as,but not limited to alkyl, cycloalkyl, substituted cycloalkyl, alkenyl,cycloalkenyl, substituted cycloalkenyl, aryl, allyl, substituted aryl,aralkyl, alkaryl, and alkynyl groups, with each group preferablycontaining from 1 carbon atom, or the appropriate minimum number ofcarbon atoms to form the group, up to 20 carbon atoms. These hydrocarbylgroups may contain heteroatoms such as, but not limited to, nitrogen,oxygen, silicon, sulfur, and phosphorus atoms. The preferred monovalentorganic groups are alkyl groups, having 1 to 4 carbon atoms, thatpreferably will not react with a living polymer.

Particularly preferred isocyanato alkoxysilane compounds includegamma-isocyanatopropyl-triethoxysilane,gamma-isothiocyanatopropyl-triethoxysilane,gamma-isocyanatopropyl-trimethoxysilane, andgamma-isothiocyanatopropyl-trimethoxysilane. Commercially availableisocyanato alkoxysilane compounds include, for example,gamma-isocyanatopropyl-trimethoxysilane, which is available under thetradename Silquest A-Link 35 (General Electric OSi Corp.).

Preferred epoxy-generating reagents include epichlorohydrin,epibromohydrin, and multi-epoxidized, high-vinyl, poly- oroligo-butadienes and poly- or oligo-isoprenes.

Other preferred Y′ functionalizing agents include triethoxysilyl propylchloride, diethoxymethylsilyl propyl chloride, and N,N-diethyl aminocarbonyl chloride.

Suitable Y′ functionalizing agents also include short-chain livingpolymers having a living terminus at one end of the chain and containinga functional group at the other end of the chain. The functional groupwill react or interact with carbon black, silica or both. In thisembodiment, the second step of the sequential functionalizationcomprises reacting the living polymer terminus of Y′ with the reactiveelectrophilic site * to form a sequentially terminated polymer that canbe represented by the general formula

X_(m)ZQTwhere

X, Z and m are as described above, Q is a spacer resulting from thebackbone of the short-chain living polymer, and T is the functionalgroup that will react or interact with carbon black, silica, or both.Short-chain refers to a polymer chain of less than about 5,000 M_(n),and preferably less than about 3,000 M_(n).

Generally, the Y′ functionalizing agent is added to the reaction mixtureof X-functionalized polymer after a sufficient reaction period hasoccurred. Preferably, the Y′ functionalizing agent is typically addedwithin about one hour of the time that the previous reactant, i.e. theX′ functionalizing agent or the chain-extending agent, is added to thepolymer. Optionally, this can be delayed if necessary. More preferably,the Y′ functionalizing agent is added within about 30 minutes of thetime that the previous reactant is added.

The living polymer is typically contacted with Y′ in a solvent ordiluent. The solvent is preferably one in which both the polymer and Y′are soluble. In one embodiment, the reaction can occur in the samemedium in which the polymerization occurred.

The amount of Y′ functionalizing agent is not limited, and can varywidely depending upon the functionalizing agent and the amount offunctionalization desired. In one embodiment, it is preferred to employfrom about 0.3 to about 1 equivalent of Y′ functionalizing agent perequivalent of initiator, more preferably, from about 0.4 to about 0.9equivalents of functionalizing agent, and even more preferably fromabout 0.5 to about 0.8 equivalents of functionalizing agent perequivalent of initiator. It will be appreciated that these numbers arebased upon the amount of initiator added to the system, and may or maynot reflect the amount of initiator that is associated with the polymer.

Preferably, at least about 25 percent of the X-functionalized polymermolecules are also functionalized with the Y′ functionalizing agent.More preferably, at least about 40 percent of the X-functionalizedpolymer molecules are also functionalized with the Y′ functionalizingagent. Even more preferably, at least about 50 percent ofX-functionalized polymer molecules are also functionalized with the Y′functionalizing agent.

It will be understood that the functionalization process of the presentinvention may result in a mixture of polymer molecules, includingX-functionalized polymer molecules, X-Y-functionalized polymermolecules, and polymer molecules that are not functionalized with X orY. The relative amounts of each of these types of polymer molecules canbe adjusted to desired levels by, for example, adjusting the amounts offunctionalizing agents used relative to polymer, and reactionconditions.

In one embodiment, a functionalized initiator is employed in preparingthe anionically polymerized living polymer, and the sequentiallyfunctionalized polymer can be described by the general formulainit

X_(m)ZY_(n)where

X, Y, Z, m, and n are as described above, and init is a functionalresidue from a functionalized initiator. Preferably, init is afunctionality or functional group that reacts or interacts with rubberor rubber fillers or otherwise has a desirable impact on filled rubbercompositions or vulcanizates. Those groups or substituents that react orinteract with rubber or rubber fillers or otherwise have a desirableimpact on filler rubber compositions or vulcanizates are known and mayinclude trialkyl tin substituents, cyclic amine groups, orsulfur-containing heterocycles. Exemplary trialkyl tin substituents aredisclosed in U.S. Pat. No. 5,268,439, which is incorporated herein byreference. Exemplary cyclic amine groups are disclosed in U.S. Pat. Nos.6,080,853, 5,786,448, 6,025,450, and 6,046,288, which are incorporatedherein by reference. Exemplary sulfur-containing heterocycles aredisclosed in WO 2004/020475, which is incorporated herein by reference.

After formation of the functionalized polymer, a processing aid andother optional additives such as oil can optionally be added to thepolymer cement. The functionalized polymer and other optionalingredients are then isolated from the solvent and preferably dried.Conventional procedures for desolventization and drying may be employed.In one embodiment, the functionalized polymer may be isolated from thesolvent by steam desolventization or hot water coagulation of thesolvent followed by filtration. Residual solvent may be removed by usingconventional drying techniques such as oven drying or drum drying.Alternatively, the polymer cement may be directly drum dried.

In a preferred embodiment, functionalizing agent X′ is NMP,functionalizing agent Y′ is gamma isocyanatopropyl-trimethoxysilane, Zis a bond, m equals 1, and n equals 1, and the sequentially terminatedpolymer is believed to be represented by the following general formula

In another preferred embodiment, X′ is NMP, Y′ is epichlorohydrin, Z isa bond, m equals 1, and n equals 1, and the sequentially terminatedpolymer is believed to be represented by the following general formula

In yet another preferred embodiment, X′ is DMI, Y′ is gammaisocyanatopropyl-trimethoxysilane, Z is a bond, m equals 1, and n equals1, and the sequentially terminated polymer is believed to be representedby the following general formula

In yet a further preferred embodiment, X′ is DMI, Y′ is epichlorohydrin,Z is a bond, m equals 1, and n equals 1, and the sequentially terminatedpolymer is believed to be represented by the following general formula

The functionalized polymers of this invention are particularly useful inpreparing tire components. These tire components can be prepared byusing the functionalized polymers of this invention alone or togetherwith other rubbery polymers. In a preferred embodiment, a mixture ofpolymers that include X-functionalized polymer molecules,X-Y-functionalized polymer molecules, and optionally other rubberypolymers are present in the mixture. The amounts of X-functionalizedpolymer molecules and X-Y-functionalized polymer molecules that arepresent can vary widely, but preferably the ratio of X-functionalizedpolymer molecules to X-Y-functionalized polymer molecules in the tireformulation is from about 0.1:1 to about 5:1, more preferably 0.2:1 toabout 4:1, even more preferably from about 0.5:1 to about 3:1 and stillmore preferably from about 0.8:1 to about 1.5:1.

Other rubbery elastomers that may be used include natural and syntheticelastomers. The synthetic elastomers typically derive from thepolymerization of conjugated diene monomers. These conjugated dienemonomers may be copolymerized with other monomers such as vinyl aromaticmonomers. Other rubbery elastomers may derive from the polymerization ofethylene together with one or more α-olefins and optionally one or morediene monomers.

Useful rubbery elastomers include natural rubber, syntheticpolyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene,poly(ethylene-co-propylene), poly(styrene-co-butadiene),poly(styrene-co-isoprene), and poly(styrene-co-isoprene-co-butadiene),poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene),polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber,epichlorohydrin rubber, and mixtures thereof. These elastomers can havea myriad of macromolecular structures including linear, branched andstar shaped. Other ingredients that are typically employed in rubbercompounding may also be added.

The rubber compositions may include fillers such as inorganic andorganic fillers. The organic fillers include carbon black and starch.The inorganic fillers may include silica, aluminum hydroxide, magnesiumhydroxide, clays (hydrated aluminum silicates), and mixtures thereof.

A multitude of rubber curing agents may be employed, including sulfur orperoxide-based curing systems. Curing agents are described in 20Kirk-Othmer, Encyclopedia of Chemical Technology, 365-468, (3^(rd) Ed.1982), particularly Vulcanization Agents and Auxiliary Materials,390-402, and A. Y. Coran, Vulcanization in Encyclopedia of PolymerScience and Engineering, (2^(nd) Ed. 1989), which are incorporatedherein by reference. Vulcanizing agents may be used alone or incombination.

Other ingredients that may be employed include accelerators, oils,waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifyingresins, reinforcing resins, fatty acids such as stearic acid, peptizers,and one or more additional rubbers.

These stocks are useful for forming tire components such as treads,subtreads, black sidewalls, body ply skins, bead filler, and the like.Preferably, the functional polymers are employed in tread formulations,and these tread formulations will include from about 10 to about 100% byweight of the functionalized polymer based on the total rubber withinthe formulation. More preferably, the tread formulation will includefrom about 35 to about 90% by weight, and more preferably from about 50to 80 % by weight of the functional polymer based on the total weight ofthe rubber within the formulation. The preparation of vulcanizablecompositions and the construction and curing of the tire is not affectedby the practice of this invention.

Preferably, the vulcanizable rubber composition is prepared by formingan initial masterbatch that includes the rubber component and filler.This initial masterbatch is mixed at a starting temperature of fromabout 25° C. to about 125° C. with a discharge temperature of about 135°C. to about 180° C. To prevent premature vulcanization (also known asscorch), this initial masterbatch generally excludes any vulcanizingagents. Once the initial masterbatch is processed, the vulcanizingagents are introduced and blended into the initial masterbatch at lowtemperatures in a final mix stage, which does not initiate thevulcanization process. Optionally, additional mixing stages, sometimescalled remills, can be employed between the masterbatch mix stage andthe final mix stage. Rubber compounding techniques and the additivesemployed therein are generally known as disclosed in Stephens, TheCompounding and Vulcanization of Rubber, in Rubber Technology (2^(nd)Ed. 1973). The mixing conditions and procedures applicable tosilica-filled tire formulations are also well known as described in U.S.Pat. Nos. 5,227,425, 5,719,207, 5,717,022, and European Patent No.890,606, all of which are incorporated herein by reference.

Where the vulcanizable rubber compositions are employed in themanufacture of tires, these compositions can be processed into tirecomponents according to ordinary tire manufacturing techniques includingstandard rubber shaping, molding and curing techniques. Typically,vulcanization is effected by heating the vulcanizable composition in amold; e.g., it is heated to about 140 to about 180° C. Cured orcrosslinked rubber compositions may be referred to as vulcanizates,which generally contain three-dimensional polymeric networks that arethermoset. The other ingredients, such as processing aides and fillers,are generally evenly dispersed throughout the vulcanized network.Pneumatic tires can be made as discussed in U.S. Pat. Nos. 5,866,171,5,876,527, 5,931,211, and 5,971,046, which are incorporated herein byreference.

In certain embodiments, the functionalized polymers of this inventionprovide carbon black, carbon black/silica, and silica filled-rubbervulcanizates with an advantageous balance of properties. Preferredvulcanizates exhibit reduced hysteresis loss, reduced wear, increasedbound rubber, and improved wet traction. Filled-rubber vulcanizatesprepared with the functionalized polymers of this invention also exhibita reduced Payne effect in some embodiments. Excellent polymerprocessability, as indicated by Mooney viscosity, can also bemaintained. These functionalized polymers can be readily prepared byterminating living polymers.

In order to demonstrate the practice of the present invention, thefollowing examples have been prepared and tested. The examples shouldnot, however, be viewed as limiting the scope of the invention. Theclaims will serve to define the invention.

EXAMPLES Example 1

To a 18.9 L reactor equipped with turbine agitator blades was added 4.8kg hexane, 1.22 kg (33 wt %) styrene in hexane, and 7.39 kg (22.1 wt %)1,3-butadiene in hexane. To the reactor was charged 11 mL of 1.68 Mbutyllithium in hexane and 3.83 mL of 1.6 M2,2′-di(tetrahydrofuryl)propane in hexane and the batch temperature wascontrolled at from 50° C. to about 58° C. After approximately 45minutes, the batch was cooled to 32° C. and a measured amount of livepoly(styrene-co-butadiene)cement was then transferred to a sealednitrogen purged 800 mL bottle. The bottle contents were then terminatedwith 1 equivalent of isopropanol, coagulated and drum dried. NMRanalysis of this base polymer indicated a styrene content of about 20percent, a block styrene content of about 4 percent, and approximately54 percent of the butadiene in the 1,2-configuration.

Example 2

A second measured amount of live poly(styrene-co-butadiene)cementprepared in Example 1 was transferred to a sealed nitrogen purgedbottle, and to this was added 1 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. The bottle contents were then mixed with 1 equivalent ofisopropanol, coagulated and drum dried.

Example 3

A third measured amount of live poly(styrene-co-butadiene)cementprepared in Example 1 was transferred to a sealed nitrogen purgedbottle, and to this was added 1 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. One equivalent of isocyanatopropyl trimethoxysilane (Silquest®A-Link 35) per equivalent of butyllithium was added and the contents ofthe bottle were further agitated at about 50° C. for about 30 minutes.The bottle contents were then mixed with about 2 equivalents of sorbitantrioleate (STO), coagulated and drum dried.

Example 4

A fourth measured amount of live poly(styrene-co-butadiene)cementprepared in Example 1 was transferred to a sealed nitrogen purgedbottle, and to this was added 1 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. One equivalent of epichlorohydrin per equivalent ofbutyllithium was added and the contents of the bottle were furtheragitated at about 50° C. for about 30 minutes. The bottle contents werethen coagulated and drum dried. The polymers of Examples 1-4 werecharacterized as set forth in Table I. TABLE I Example No. 1 2 3 4 M_(n)(kg/mol) 123 88 81 72 M_(w)/M_(n) 1.04 1.11 1.71 1.16 T_(g) (° C.) −33−33 −33 −34

Examples 5-8

The rubber of Examples 1-4 were employed in carbon black tireformulations designated Examples 5-8, respectively. The formulations arepresented in Table II. TABLE II Example No. (weight parts) 5 6 7 8Initial Formulation Rubber Example 100 100 100 100 Carbon Black 55 55 5555 Wax 1 1 1 1 Antiozonant 0.95 0.95 0.95 0.95 Zinc Oxide 2.5 2.5 2.52.5 Stearic Acid 2 2 2 2 Aromatic Oil 10 10 10 10 Total 171.45 171.45171.45 171.45 Final Formulation Initial 171.45 171.45 171.45 171.45Sulfur 1.3 1.3 1.3 1.3 Accelerators 1.9 1.9 1.9 1.9 Total 174.65 174.65174.65 174.65

Each carbon black rubber compound was prepared in two stages, which arenamed Initial (Masterbatch) and Final. In the initial part, the polymerfrom Example 1, 2, 3 or 4 was mixed with carbon black, an antiozonant,stearic acid, wax, aromatic oil, and zinc oxide, in a 65 g Banbury mixeroperating at 60 RPM and 133° C. Specifically, the polymer was firstplaced in the mixer, and after 0.5 minutes, the remaining ingredientsexcept the stearic acid were added. The stearic acid was then addedafter 3 minutes. The initials were mixed for 5-6 minutes. At the end ofthe mixing the temperature was approximately 165° C. The example wastransferred to a mill operating at a temperature of 60° C., where it wassheeted and subsequently cooled to room temperature.

The finals were mixed by adding the initials and the curative materialsto the mixer simultaneously. The initial mixer temperature was 65° C.and it was operating at 60 RPM. The final material was removed from themixer after 2.25 minutes when the material temperature was between 100and 105° C.

Test specimens of each rubber formulation were prepared by cutting outthe required mass from an uncured sheet (about 2.5 mm to 3.81 mm thick),and cured within closed cavity molds under pressure for 15 minutes at171° C. The test specimens were then subjected to various physicaltests, and the results of these tests are reported in Table III. Mooneyviscosity measurement was conducted on uncured rubber at 130° C. using alarge rotor. The Mooney viscosity was recorded as the torque when therotor has rotated for 4 minutes. The sample is preheated at 130° C. for1 minute before the rotor starts. Modulus at 300%, and tensile strengthwere measured according to ASTM D 412 (1998) Method B. Dynamicproperties were determined by using a RDA (Rheometrics DynamicAnalyzer). Strain sweep experiments were conducted at a frequency of 10Hertz (Hz) and temperatures of 0 and 50°C., with strain sweeping from 0%to 10%. )G is the change in GN at 0.25% from GN at 14.75%. Payne effect(AG′) data were obtained from the strain sweep experiment. Temperaturesweep experiments were conducted with a frequency of 31.4 rad/sec using0.5% strain for temperature ranging from −100° C. to −10° C., and 2%strain for the temperature ranging from −10° C. to 100° C.

Bound rubber, a measure of the percentage of rubber bound, through someinteraction, to the filler, was determined by solvent extraction withtoluene at room temperature. More specifically, a test specimen of eachuncured rubber formulation was placed in toluene for three days. Thesolvent was removed and the residue was dried and weighed. Thepercentage of bound rubber was then determined according to the formula% bound rubber=(100(W _(d) −F))/R

where W_(d) is the weight of the dried residue, F is the weight of thefiller and any other solvent insoluble matter in the original sample,and R is the weight of the rubber in the original sample. TABLE IIIExample No. 5 6 7 8 ML₁₊₄@130° C. 25.5 43.8 52.9 42.0 t₅₀ (min) 3.062.32 2.40 1.95 300% Modulus @ 23° C. (MPa) 11.66 14.20 14.19 15.17Tensile @ Break @ 23° C. (MPa) 14.56 17.61 18.68 18.02 tan δ 0.5% E (0°C.) 0.2290 0.3088 0.2888 0.2920 )G′ (50° C.) (MPa) 4.2749 0.6881 0.62330.6378 tan δ 0.5% E (50° C.) 0.2574 0.1260 0.1505 0.1675 Bound Rubber(%) 7.6 52.3 47.7 38.5

Examples 9-12

The rubber of Examples 1-4 were employed in carbon black/silica tireformulations designated as Examples 9-12, respectively. The formulationsare presented in Table IV. TABLE IV Example No. (weight parts) 9 10 1112 Initial Formulation Rubber Example 100 100 100 100 Carbon Black 35 3535 35 Silica 30 30 30 30 Antiozonant 0.95 0.95 0.95 0.95 Stearic Acid1.5 1.5 1.5 1.5 Aromatic Oil 10 10 10 10 Total 177.45 177.45 177.45177.45 Remill Initial 177.45 177.45 177.45 177.45 Silane Shielding Agent4.57 4.57 4.57 4.57 Total 182.02 182.02 182.02 182.02 Final FormulationInitial 182.02 182.02 182.02 182.02 Sulfur 1.7 1.7 1.7 1.7 Zinc Oxide2.5 2.5 2.5 2.5 Pre-Vulcanization Inhibitor 0.25 0.25 0.25 0.25Accelerators 2.0 2.0 2.0 2.0 Total 188.47 188.47 188.47 188.47

Each carbon black/silica rubber compound was prepared in three stagesnamed Initial, Remill and Final. In the initial part, the polymer fromExamples 1, 2, 3 or 4 was mixed with carbon black, silica, anantioxidant, stearic acid, and aromatic oil in a 65 g Banbury mixeroperating at 60 RPM and 133° C. Specifically, the polymer was firstplaced in the mixer, and after 0.5 minutes, the remaining ingredientsexcept the stearic acid were added. The stearic acid was then addedafter 3 minutes. The initials were mixed for 5-6 minutes. At the end ofthe mixing the temperature was approximately 165° C. The sample wascooled to less that about 95° C. and transferred to a remill mixer.

In the remill stage, the initial formulation and silane shielding agentwere simultaneously added to a mixer operating at about 60 RPM. Theshielding agent employed in these examples was EF(DiSS)-60, availablefrom Rhein Chemie Corp. The starting temperature of the mixer was about94° C. The remill material was removed from the mixer after about 3minutes, when the material temperature was between 135 and 150° C.

The finals were mixed by adding the remills, zinc oxide and the curativematerials to the mixer simultaneously. The initial mixer temperature was65° C. and it was operating at 60 RPM. The final material was removedfrom the mixer after 2.25 minutes when the material temperature wasbetween 100 and 105° C. Test specimens were prepared and subjected tovarious physical tests as for Examples 5-8 above. The results of thesetests are reported in Table V. TABLE V Example No. 9 10 11 12 ML₁₊₄@130°C. 39.5 79.8 76.1 91.6 t₅₀ (min) 4.4  3.83  3.95 4.79 300% Modulus @12.9  0*  0* 11.8 23° C. (MPa) Tensile @ Break @ 15.7 14.1 17.1 15.0 23°C. (MPa) tan δ 0.5% E (0° C.) 0.2138   0.2433    .02769 0.2393 )G′ (50°C.) (MPa) 5.835   2.012   1.569 2.786 tan δ 0.5% E (50° C.) 0.2335  0.1980   0.1667 0.1903 Bound Rubber (%) 24.1 31.5 45.6 N/A*Sample broke prior to measurement.

Example 13

To a 19 L reactor equipped with turbine agitator blades was added 5.2 kghexane, 1.2 kg (34 wt %) styrene in hexane, and 7.1 kg (22.5 wt %)1,3-butadiene in hexane. To the reactor was charged 18.6 mmolbutyllithiu m and 6.1 mmol of a polar modifier and the batch temperaturewas controlled at from 65° C. to about 70° C. After approximately 1½hours, the batch was cooled to 32° C. and a measured amount of the livepoly(styrene-co-butadiene)cement was transferred to a sealed nitrogenpurged 800 mL bottle. The bottle contents were then terminated with 1equivalent of isopropanol per equivalent of butyllithium, coagulated anddrum dried.

Example 14

A live poly(styrene-co-butadiene)cement was prepared as in Example 13and transferred to a sealed nitrogen purged bottle, and to this wasadded 1 equivalent of 3-glycidoxypropyltrimethoxysilane (GPMOS) perequivalent of butyllithium. The contents of the bottle were agitated atabout 50° C. for about 30 minutes. A measured amount of the GPMOSterminated polymer was then mixed with 1 equivalent of isopropanol,coagulated and drum dried.

Examples 15-16

To a 19 L reactor equipped with turbine agitator blades was added 7.0 kghexane and 7.0kg (21 wt %) 1,3-butadiene in hexane. To the reactor wascharged 76 mmol tributyl tin lithium and 25 mmol of a polar modifier andthe batch temperature was controlled at from 55° C. to about 60° C.After approximately 1½ hours, the batch was cooled to 32° C. A measuredamount of the tributyl tin butadiene lithium cement was transferred to asealed nitrogen purged 800 mL bottle containing a measured amount of theGPMOS terminated polymer prepared in Example 14. The amount of tributyltin butadiene lithium transferred was 1 equivalent per GPMOS terminatedpolymer for Example 15 and 2 equivalents for per GPMOS terminatedpolymer Example 16. The content of the each bottle was agitated at 50°C. for 1 hour, isolated, and drum dried.

The polymers of Examples 13-16 were characterized as set forth in TableVI. TABLE VI Example No. 13 14 15 16 M_(n) (kg/mol) 111 153 219 167M_(w)/M_(n) 1.04 1.21 2.76 3.97 T_(g) (° C.) −35.5 −35.5 −35.5 −35.5 Sn(ppm) N/A N/A 918 1474 Si (ppm) N/A 501 578 431

Examples 17-20

The rubber of Examples 13-16 were employed in carbon black tireformulations as for Examples 5-8. Specifically, the rubber of Example 13was employed in Example 17, Example 14 was employed in Example 18,Example 15 was employed in Example 19, and Example 16 was employed inExample 20.

Test specimens were prepared and subjected to various physical tests asfor Examples 5-8 above. The results of these tests are reported in TableVII. TABLE VII Example No. 17 18 19 20 ML₁₊₄@130° C. 21.5 51.8 67.6 63.6MH-ML @171° C. (kg-cm) 16.99 17.63 16.10 16.09 t₅₀ @171° C. (min) 3.12.8 2.8 2.8 300% Modulus @ 23° C. (MPa) 10.71 13.92 13.83 14.20 TensileStrength @23° C. (MPa) 13.67 18.29 16.98 18.22 Temp. Sweep tan δ 0.5% E,0.235 0.257 .262 0.260 5 Hz, 0° C. Temp. Sweep tan δ 2% E, 0.281 0.2320.214 0.217 5 Hz, 50° C. Strain Sweep RDA tan δ 5% E, 0.275 0.185 0.1680.165 1 Hz, 50° C. )G′ (50° C.) (MPa) 5.124 2.299 1.911 1.781 BoundRubber (%) 22.1 30.2 32.7 31.7

Examples 21-24

The rubber of Examples 13-16 were employed in carbon black/silica tireformulations Examples 21-24, respectively. The formulations were mixedas described above for Examples 9-12.

Test specimens were prepared and subjected to various physical tests asfor Examples 9-12 above. The results of these tests are reported inTable VIII. TABLE VIII Example No. 21 22 23 24 ML₁₊₄@130° C. 55.5 98.596.6 92.6 MH-ML @171° C. (kg-cm) 23.14 16.84 16.75 17.01 t₅₀ @171° C.(min) 7.8 5.8 6.2 5.8 300% Modulus @ 23° C. (MPa) 8.76 13.46 12.88 13.17Tensile Strength @23° C. (MPa) 12.13 15.31 15.40 15.16 Temp. Sweep tan δ0.5% E, 0.214 0.297 0.291 0.284 5 Hz, 0° C. Temp. Sweep tan δ 2% E,0.241 0.163 0.172 0.172 5 Hz, 50° C. Strain Sweep RDA tan δ 5% E, 0.2440.156 0.158 0.160 1 Hz, 50° C. )G′ (50° C.) (MPa) 7.529 1.847 1.7471.741 Bound Rubber (%) 21.7 78.6 75.0 72.6

Example 25

A live poly(styrene-co-butadiene)cement was prepared as in Example 1,and a measured amount was terminated with 1 equivalent of isopropanol,coagulated and drum dried. The Tg of the polymer was about −31.1° C.

Example 26

A second measured amount of the live poly(styrene-co-butadiene)cementprepared in Example 25 was transferred to a sealed nitrogen purgedbottle, and to this was added 0.9 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. The bottle contents were then mixed with 1 equivalent ofisopropanol, coagulated and drum dried.

Example 27

A third measured amount of live poly(styrene-co-butadiene)cementprepared in Example 25 was transferred to a sealed nitrogen purgedbottle, and to this was added 0.9 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. Approximately 0.9 equivalent of triethoxysilyl propyl chlorideper equivalent of butyllithium was added and the contents of the bottlewere further agitated at about 50° C. for about 30 minutes. The bottlecontents were then mixed with about 2 equivalents of sorbitan trioleate(STO), coagulated and drum dried.

Example 28

A fourth measured amount of live poly(styrene-co-butadiene)cementprepared in Example 25 was transferred to a sealed nitrogen purgedbottle, and to this was added 0.9 equivalent of1,3-dimethylimidazolidinone (DMI) per equivalent of butyllithium. Thecontents of the bottle were agitated at about 50° C. for about 30minutes. Approximately 0.9 equivalent of diethoxymethylsilyl propylchloride per equivalent of butyllithium was added and the contents ofthe bottle were further agitated at about 50° C for about 30 minutes.The bottle contents were then coagulated and drum dried.

Example 29

A fifth measured amount of live poly(styrene-co-butadiene)cementprepared in Example 25 was transferred to a sealed nitrogen purgedbottle, and to this was added 0.9 equivalent of monoglycidyl etherterminated poly(dimethylsiloxane) having an average molecular weightM_(n) of about 5000. The contents of the bottle were agitated at about50° C. for about 30 minutes. Approximately 0.9 equivalent ofdiethylcarbamyl chloride per equivalent of butyllithium was added andthe contents of the bottle were further agitated at about 50° C. forabout 30 minutes. The bottle contents were then coagulated and drumdried.

Example 30

A sixth measured amount of live poly(styrene-co-butadiene)cementprepared in Example 25 was transferred to a sealed nitrogen purgedbottle, and to this was added ).9 equivalent of monoglycidyl etherterminated poly(dimethylsiloxane) having an average molecular weightM_(n) of about 5000. The contents of the bottle were agitated at about50° C. for about 30 minutes. Approximately 0.9 equivalent of1-(3-bromopropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentane perequivalent of butyllithium was added and the contents of the bottle werefurther agitated at about 50° C. for about 30 minutes. The bottlecontents were then coagulated and drum dried. The polymers of Examples25-30 were characterized as set forth in Table IX. TABLE IX Example No.25 26 27 28 29 30 M_(n) (kg/mol) 113 122 112 114 123 115 M_(w)/M_(n)1.05 1.09 1.04 1.07 1.1 1.04 Coupling (%) none 13 3 7 14 3

Examples 31-36

The rubber of Examples 25-30 were employed in carbon black tire 5formulations Examples 31-36, respectively. The formulations were mixedas described above for Examples 5-8. Test specimens were prepared andsubjected to various physical tests as for Examples 5-8 above. Theresults of these tests are reported in Table X. TABLE X Example No. 3132 33 34 35 36 ML₁₊₄@130° C. 26.67 41 41.25 41.47 32.37 32.97 MH-ML@171° C. (kg-cm) 18.21 16.48 16.72 16.64 17.95 18.61 t₅₀ @171° C. (min)3.6 2.35 2.15 2.3 3.3 3.3 300% Modulus @23° C. (MPa) 11.17 14.5 14.9113.84 10.02 12.22 Tensile @ Break @23° C. (MPa) 17.68 18.83 17.49 19.1515.47 17.29 Temp. Sweep tan δ @0° C. 0.251 0.328 0.330 0.336 0.257 0.251Temp. Sweep tan δ @ 50° C. 0.270 0.176 0.165 0.192 0.250 0.268 StrainSweep RDA tan δ 5% E, 50° C. 0.246 0.119 0.109 0.116 0.238 0.225 )G′@50° C. (MPa) 4.698 0.789 0.637 0.654 4.324 4.293 Bound Rubber (%) 15.240.1 39.4 40.0 17.2 —

Examples 37-41

The rubber of Examples 25-29 were employed in carbon black/silica tireformulations Examples 37-41, respectively. The formulations were mixedas described above for Examples 9-12.

Test specimens were prepared and subjected to various physical tests asfor Examples 9-12 above. The results of these tests are reported inTable XI. TABLE XI Example No. 37 38 39 40 41 ML₁₊₄@130° C. 65.6 98.699.3 99.7 91.3 MH-ML @171° C. (kg-cm) 24.13 17.98 17.06 18.71 19.69 t₅₀@171° C. (min) 7.3 5.6 5.6 5.25 6.5 300% Modulus @23° C. (MPa) 9.3110.12 9.87 11.17 — Tensile @ Break @23° C. (MPa) 13.43 14.74 15.27 15.9715.07 Temp. Sweep tan δ @0° C. 0.218 0.265 0.263 0.267 0.286 Temp. Sweeptan δ @ 50° C. 0.232 0.198 0.194 0.208 0.188 Strain Sweep RDA tan δ 5%E, 50° C. 0.241 0.172 0.177 0.107 0.202 Dynastat tan δ 50° C. 0.2260.169 0.170 0.162 0.188 )G′ @50° C. (MPa) 7.448 2.870 2.461 2.725 3.579Bound Rubber (%) 22.9 29.1 31.3 31.4 50.0

Various modifications and alterations that do not depart from the scopeand spirit of this invention will become apparent to those skilled inthe art. This invention is not to be duly limited to the illustrativeembodiments set forth herein.

1. A vulcanizate comprising: a vulcanized rubber formulation comprisingat least one vulcanized rubber and a filler, where the at least onevulcanized rubber includes a vulcanizate of a sequentiallyfunctionalized polymer that is prepared by reacting an anionicallypolymerized living polymer with a functionalizing agent X′ to produce anend-functionalized polymer that will react or interact with carbonblack, silica, or both and that comprises a reactive electrophilic ornucleophilic site; and reacting the reactive site with a functionalizingagent Y′ to produce a sequentially functionalized polymer that willreact or interact with carbon black and silica.
 2. The vulcanizate ofclaim 1, where the anionically polymerized living polymer is a copolymerof styrene and 1,3-butadiene.
 3. The vulcanizate of claim 1, where X′comprises 1,3-dimethylimidazolidinone, N-methylpyrrolidinone,dicyclohexylcarbodiimide, benzonitrile, a substituted nitrile, asubstituted aziridine, a thiazoline, a dialkylaminobenzaldehyde, abis(dialkylamino)benzophenone, a substituted epoxy compound,N-methylcaprolactam, a substituted Schiff base, a substitutedstyrylmethyl derivative, vinyl pyridine, a short block ofpolyvinylpyridine, a polysulfoxide, a poly(carbodiimide), apoly(meth)acrylamide, a poly(aminoalkyl(meth)acrylate),polyacrylonitrile, polyethylene oxide, butyl glycidyl ether,monoglycidyl siloxane, polysiloxane with epoxide endgroups, diphenylethylene, or a functionalized styrene.
 4. The vulcanizate of claim 1,where X′ comprises 1,3-dimethylimidazolidinone,3-glycidoxypropyltrimethoxysilane, N-methylpyrrolidinone, ormonoglycidyl ether terminated poly(dimethylsiloxane).
 5. The vulcanizateof claim 1, where Y′ comprises a silane, alkoxy silane, alkoxy alkylsilane, alkoxy halo alkyl silane, epoxy-generating reagent, substitutedacid chloride, substituted isocyanate, substituted benzylic halide,substituted allylic halide, substituted α,β-unsaturated ketone,α,β-unsaturated ester, α,β-unsaturated amide, orbis(dialkylamino)phosphoryl chloride.
 6. The vulcanizate of claim 1,where Y′ comprises gamma-isocyanatopropyl-triethoxysilane,gamma-isothiocyanatopropyl-triethoxysilane, gamma-isocyanatopropyl-trimethoxysilane, gamma-isothiocyanatopropyl-trimethoxysilaneepichlorohydrin, epibromohydrin, triethoxysilyl propyl chloride,diethoxymethylsilyl propyl chloride, and diethylcarbamyl chloride,1-(3-bromopropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentane, or amulti-epoxidized, high-vinyl, poly- or oligo-butadiene or a poly- oroligo-isoprene.
 7. The vulcanizate of claim 1, where Y′ comprises ashort-chain polymer group.
 8. The vulcanizate of claim 1, where thefiller includes carbon black, silica, or a mixture thereof.
 9. Thevulcanizate of claim 1, where the vulcanizate further includes avulcanized natural rubber or vulcanized synthetic rubber other than thesequentially functionalized polymer.
 10. A method for preparing asequentially functionalized polymer, the method comprising: reacting ananionically polymerized living polymer with a functionalizing agent X′to produce an end-functionalized polymer that will react or interactwith carbon black, silica, or both and that comprises a reactiveelectrophilic or nucleophilic site; and reacting the reactive site witha functionalizing agent Y′ to produce a sequentially functionalizedpolymer that will react or interact with carbon black and silica. 11.The method of claim 10, where the anionically polymerized living polymeris a copolymer of styrene and 1,3-butadiene.
 12. The method of claim 10,where X′ comprises 1,3-dimethylimidazolidinone, N-methylpyrrolidinone,dicyclohexylcarbodiimide, benzonitrile, a substituted nitrile, asubstituted aziridine, a thiazoline, a dialkylaminobenzaldehyde, abis(dialkylamino)benzophenone, a substituted epoxy compound,N-methylcaprolactam, a substituted Schiff base, a substitutedstyrylmethyl derivative, vinyl pyridine, a short block ofpolyvinylpyridine, a polysulfoxide, a poly(carbodiimide), apoly(meth)acrylamide, a poly(aminoalkyl(meth)acrylate),polyacrylonitrile, polyethylene oxide, butyl glycidyl ether,monoglycidyl siloxane, polysiloxane with epoxide endgroups, diphenylethylene, or a functionalized styrene.
 13. The method of claim 10, whereX′ comprises 1,3-dimethylimidazolidinone,3-glycidoxypropyltrimethoxysilane, N-methylpyrrolidinone, ormonoglycidyl ether terminated poly(dimethylsiloxane).
 14. The method ofclaim 10, where Y′ comprises a silane, alkoxy silane, alkoxy alkylsilane, alkoxy halo alkyl silane, epoxy-generating reagent, substitutedacid chloride, substituted isocyanate, substituted benzylic halide,substituted allylic halide, substituted α,β,-unsaturated ketone,α,β,-unsaturated ester, α,β-unsaturated amide, orbis(dialkylamino)phosphoryl chloride.
 15. The method of claim 10, whereY′ comprises gamma-isocyanatopropyl-triethoxysilane,gamma-isothiocyanatopropyl-triethoxysilane,gamma-isocyanatopropyl-trimethoxysilane,gamma-isothiocyanatopropyl-trimethoxysilane epichlorohydrin,epibromohydrin, triethoxysilyl propyl chloride, diethoxymethylsilylpropyl chloride, and diethylcarbamyl chloride,1-(3-bromopropyl)-2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentane, or amulti-epoxidized, high-vinyl, poly- or oligo-butadiene or a poly- oroligo-isoprene.
 16. The method of claim 10, where Y′ comprises ashort-chain polymer group.
 17. The method of claim 10, furthercomprising the step of reacting the reactive site with a chain-extendinggroup Z to form a chain-extended functionalized polymer that comprises areactive electrophilic or nucleophilic site.
 18. A functionalizedpolymer defined by the formula

X_(m)ZY_(n) where

is an anionically polymerized polymer segment, X comprises a firstfunctional group that will react or interact with carbon black, silica,or both, Y comprises a second functional group that will react orinteract with carbon black, silica, or both, Z is a bond or achain-extending group, and .m and n are each integers from 1 to about50, with the proviso that when X will react or interact with carbonblack but not with silica, Y will react or interact with silica, andwhen X will react or interact with silica but not with carbon black, Ywill react or interact with carbon black.